<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>导航条</title>
    <style>
        * {margin: 0; padding: 0;}
        ul {
            list-style: none;
            display: flex;
            margin: 100px auto;
            width: 1200px;
            height: 70px;
            font-size: 18px;
            text-align: center;
            line-height: 70px;
            background-color: lightgray;
        }
        a {
            color: white;
            text-decoration: none;
        }
        a:hover {
            background-color: rgb(115, 150, 180);
        }
        li, a {
            display: block;
            flex: 1 1 150px;
        }
        
    </style>
</head>
<body>
<!-- TODO 弹性盒制作导航条-->
<ul>
    <li><a href="#">HTML/CSS</a></li>
    <li><a href="#">Browser Side</a></li>
    <li><a href="#">Server Side</a></li>
    <li><a href="#">Programing</a></li>
    <li><a href="#">XML</a></li>
    <li><a href="#">Web Building</a></li>
    <li><a href="#">Reference</a></li>
</ul>
</body>
</html>